Breast carcinoma is the second leading cause of cancer deaths among women in the U.S. (Jemal et al., 2005. CA Cancer J Clin 55:10-30). Early detection and diagnosis of breast cancer significantly improves 5-year survival rates (Ries et al., 2005. SEER Cancer statistics review. National Cancer Institute, Bethesda, Md.). Currently the only approved screening method for the detection for breast cancer is mammography.
In the past few years, several large-scale proteomic studies have begun to characterize the proteome of breast cancer (Pucci-Minafra et al., 2006. Proteomics 6:2609-25; Celis et al., 2004. Mol Cell Proteomics 3:327-44; Hudelist et al., 2006. Proteomics 6:1989-2002). This high-throughput strategy leads to complex data sets that, while rich in information, are often not very useful in predicting proteins that may be sensitive and specific biomarkers for the disease.
Epithelial ovarian cancer is the deadliest reproductive tract malignancy of women in Western countries (Ozols et al., 2004. Cancer Cell 5:19-24). Ovarian cancer survival rates at years are only 30% for women diagnosed with distant metastases; however, the percentage survival climbs to 90% for women diagnosed with disease confined to the ovary (Hayat et al., 2007. Oncologist 12:20-37). Unfortunately, fewer than 25% of women are diagnosed when the disease is confined, due primarily to the lack of screening tests capable of detecting ovarian cancers early.
Reliable biomarkers are not available for the majority of cancers and precancerous conditions. Specifically, there is a lack of secreted biomarkers that can be detected through non-invasive assays such as blood tests. Without convenient and easily accessible screening tests for cancers and precancerous conditions, diagnostic delays will continue to plague the health care system and thwart efforts to detect and treat malignancies in their earliest stages.